105859-44-7Relevant articles and documents
Stereochemical Determination of Tuscolid/Tuscorons and Total Synthesis of Tuscoron D and E: Insights into the Tuscolid/Tuscoron Rearrangement
G?ricke, Bj?rn,Bieber, Michelle Fernandez,Mohr, Kathrin E.,Menche, Dirk
, p. 13019 - 13023 (2019)
The stereochemistry of the structurally unique myxobacterial polyketides tuscolid/tuscorons was determined by a combination of high-field NMR studies, molecular modeling, and chemical derivatization and confirmed by a modular total synthesis of tuscorons D and E. Together with the discovery of three novel tuscorons, this study provides detailed insight into the chemically unprecedented tuscolid/tuscoron rearrangement cascade.
Asymmetric synthesis of (R)-3-hydroxy-2-methylpropanoate ('Roche Ester') and derivatives via biocatalytic C=C-bond reduction
Stueckler, Clemens,Winkler, Christoph K.,Bonnekessel, Melanie,Faber, Kurt
, p. 2663 - 2666 (2010)
Enoate reductases from the 'old yellow enzyme' family were employed for the asymmetric bioreduction of methyl 2-hydroxymethylacrylate and its O-allyl, O-benzyl and O-TBDMS derivatives to furnish (R)-configurated methyl 3-hydroxy-2-methylpropionate products in up to >99% ee Variation of the O-protective group had little influence on the stereoselectivity, but a major impact on the reaction rate.
Callipeltosides A, B and C: Total Syntheses and Structural Confirmation
Frost, James R.,Pearson, Colin M.,Snaddon, Thomas N.,Booth, Richard A.,Turner, Richard M.,Gold, Johan,Shaw, David M.,Gaunt, Matthew J.,Ley, Steven V.
, p. 13261 - 13277 (2015)
Since their isolation almost 20 years ago, the callipeltosides have been of long standing interest to the synthetic community owing to their unique structural features and inherent biological activity. Herein we present our full research effort that has led to the synthesis of these molecules. Key aspects of our final strategy include 1) synthesis of the C1-C9 pyran core (5) using an AuCl3-catalysed cyclisation; 2) formation of C10-C22 vinyl iodide (55) by sequential bidirectional Stille reactions and 3) diastereoselective union of these advanced fragments by means of an alkenylzinc addition (d.r.=91:9 at C9). The common callipeltoside aglycon (4) was completed in a further five steps. Following this, all three sugar fragments were appended to provide the entire callipeltoside family. In addition to this, D-configured callipeltose B was synthesised and appended to the callipeltoside aglycon. The 1H NMR spectrum of this molecule was found to be significantly different to the natural isolate, further supporting our assignment of callipeltoside B (2). Easy as A, B, C: The entire callipeltoside family of natural products have been synthesised in a highly convergent manner. This account details our full research effort and presents further evidence to aid in the stereochemical assignment of the glycosidic linkages present in callipeltosides B and C (see scheme).
Total synthesis of the tubulin inhibitor WF-1360f based on macrocycle formation through ring-closing alkyne metathesis
Neuhaus, Christian M.,Liniger, Marc,Stieger, Martin,Altmann, Karl-Heinz
, p. 5866 - 5870 (2013)
Key steps in this total synthesis of the antimitotic natural product WF-1360F (3) include the formation of the macrocycle through ring-closing alkyne metathesis and the subsequent conversion of the ensuing alkyne moiety into an E-configured double bond. As illustrated by the synthesis of 4, the macrocyclic vinyl iodide 2 can also serve as a common precursor for the synthesis of side-chain-modified rhizoxin analogues (see scheme; TIPS=triisopropylsilyl). Copyright
Asymmetrization of 2-methylpropane-1,3-diol by Mucor miehei lipase-catalyzed benzoylation in organic solvent
Santaniello, Enzo,Casati, Silvana,Ciuffreda, Pierangela,Gamberoni, Luca
, p. 3177 - 3179 (2004)
Asymmetrization of prochiral 2-methylpropane-1,3-diol by Mucor miehei lipase (MML)-catalyzed acylation with vinyl benzoate affords the corresponding (S)-monobenzoate (65% ee), that can be obtained enantiomerically pure in 40% yield by a sequential benzoyl
Total Synthesis and Stereochemical Assignment of Callyspongiolide
Zhou, Jingjing,Gao, Bowen,Xu, Zhengshuang,Ye, Tao
, p. 6948 - 6951 (2016)
Total synthesis of four callyspongiolide stereoisomers led to unambiguous assignment of relative and absolute stereochemistry of the natural product. Key features of the convergent, fully stereocontrolled route include the use of Krische allylation, Kiyooka Aldol reaction, Kociénski-Julia olefination, Still-Gennari olefination, Yamaguchi macrocyclization, and Sonogashira coupling reaction. Biological evaluation of the synthesized compounds against an array of cancer cells revealed that the stereochemistry of the macrolactone core played an important role.
Modular Fragment Synthesis and Bioinformatic Analysis Propose a Revised Vancoresmycin Stereoconfiguration
Adamek, Martina,Essig, Sebastian,Kurz, Michael,Menche, Dirk,Sch?nenbroicher, Max,Seul, Maximilian,Spindler, Stefanie,Wingen, Lukas M.,Ziemert, Nadine
supporting information, p. 1175 - 1180 (2021/01/13)
Elaborate fragments of the proposed stereostructure of the complex polyketide antibiotic vancoresmycin have been synthesized in a stereoselective fashion based on a modular and convergent approach. Significant nuclear magnetic resonance differences in one of these subunits compared with the natural product question the proposed stereoconfiguration. Consequently, an extensive bioinformatics analysis of the biosynthetic gene cluster was carried out, leading to a revised stereoconfigurational proposal for this highly potent antibiotic.
Ring-closing metathesis approaches towards the total synthesis of rhizoxins
Altmann, Karl-Heinz,Liniger, Marc,Neuhaus, Christian M.
supporting information, (2020/10/18)
Efforts are described towards the total synthesis of the bacterial macrolide rhizoxin F, which is a potent tubulin assembly and cancer cell growth inhibitor. A significant amount of work was expanded on the construction of the rhizoxin core macrocycle by ring-closing olefin metathesis (RCM) between C(9) and C(10), either directly or by using relay substrates, but in no case was ringclosure achieved. Macrocycle formation was possible by ring-closing alkyne metathesis (RCAM) at the C(9)/C(10) site. The requisite diyne was obtained from advanced intermediates that had been prepared as part of the synthesis of the RCM substrates. While the direct conversion of the triple bond formed in the ring-closing step into the C(9)-C(10) E double bond of the rhizoxin macrocycle proved to be elusive, the corresponding Z isomer was accessible with high selectivity by reductive decomplexation of the biscobalt hexacarbonyl complex of the triple bond with ethylpiperidinium hypophosphite. Radical-induced double bond isomerization, full elaboration of the C(15) side chain, and directed epoxidation of the C(11)-C(12) double bond completed the total synthesis of rhizoxin F.
